Carver County Attorney Mark Metz and Chaska Police Chief Scott Knight have expunged 40 traffic convictions and removed them from court records, saying that the ex-officer who wrote the tickets was likely profiling Latinos.

The tickets date back over the 14-year career of Joshua Lawrenz, a Chaska police officer who was fired in 2015 after an investigation found he had targeted Latino residents.

Lawrenz appealed his firing to an arbitrator, who ruled against him saying that he relied on “racial and ethnic stereotypes” in deciding whom to pull over and where to patrol.

In each of the 40 expunged cases Lawrenz was the only witness to the alleged violation, Knight said.

“We can’t believe him,” Knight said. “Because of his conduct in the case that got him terminated, justice required that we go back and review the cases where he was the officer issuing a citation.”

The county attorney’s office reviewed Lawrenz’s cases, paying close attention to those where the defendant had a Hispanic last name, Knight said.

Prosecutors focused on traffic tickets rather than criminal or more serious charges, because Lawrenz would have issued the tickets by himself, Knight said.

“On major cases or anything beyond a citation, he would not have been there alone,” he said. “But to say he didn’t carry his biases into those cases is a question we’ll never know.”

Knight put Lawrenz on administrative leave in August 2014, shortly after residents went to the chief’s office to complain.

Residents spoke out again a month later at a City Council meeting, including one elderly man who said Lawrenz handcuffed him and threw him to the ground while arresting him.

Another resident said Lawrenz sat in his squad car at the end of her block for several days before stopping her. She said he gave her a ticket for not having a driver’s license, telling her he wanted to send all people without licenses back to Mexico.

Knight said his department has always had a “strong connection” with the growing Latino community in Chaska.

“To this day I still see some of those witnesses,” he said. “Our relationship couldn’t be better. They know it was this one guy, and not the police department. And they know we took care of it.”

Greg Stanley is an environmental reporter for the Star Tribune. He has previously covered water issues, development and politics in Florida’s Everglades and in northern Illinois.